- Stable within ±0.01% per year
- 18 Models values from 1 µH to 10 H
- Low, known temperature coefficient
- 3 year warranty included
- Calibration accredited to ISO-17025 included
- Minimized connection errors
- Toroidal - free from external fields
IET continues to produce the 1482 standard inductors to the same exacting specs as General Radio. These standard inductors are accurate, highly stable standards of self inductance for use as a low frequency reference of working standard in the laboratory.
Records extending over 40 years, including those of standard inductors that traveled to national laboratories in several countries for calibration, show long-term stability well within ±0.01%/year, typically <10 ppm/year
Each standard inductor is a uniformly wound toroid on a ceramic core. It has a negligible external magnetic field and hence essentially no pickup from external fields. The inductor is resiliently supported in a mixture of ground cork and silica gel, after which the whole assembly is cast with a poƫting compound into a cubical aluminum case.
Values of 500 μH and above have three terminals, 2 for inductor leads and the third connected to the case, to provide either a 2 or 3 terminal standard. Inductors with <500 μH inductance values have three additional terminals to allow for switching between a short circuit and the inductance value which minimizes connection errors. This allows the user to perform short compensation without disconnecting leads from the inductor. A ground strap is moved to the Lo terminal when short compensation is performed and back to L for measurement of the inductance. When the same connections are used in both measurements, the inductance value is independent of the external lead inductance even for values much less than 200 μH.
For comparing other inductors with these standards, the 1689 or 1693 Digibridge is recommended.
BASIC SPECIFICATION (Full specifications can be found on the datasheet)
Calibration: A certificate of calibration that is accredited by A2LA to ISO-17025 is provided with each unit, giving measured values of inductance at 100, 200, 400, and 1000 Hz, with test conditions and method of measurements specified. These values are obtained by comparison, to a precision, typically, of better than 0.005%, with standards whose absolute values, traceable to the International System of Units (SI), are known to an accuracy typically of (0.02%+0.1μH) at 100 Hz; (0.1%+0.1 μH for the 1482-B).
Stability: Inductance change is less than 0.01% per year.